From d501cce0f1e3633a694968b6df3f2352ba2edf79 Mon Sep 17 00:00:00 2001 From: eleksir Date: Wed, 15 May 2019 18:25:59 +0300 Subject: [PATCH] Updated README.md --- README.md | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/README.md b/README.md index 8a1df93..17eb81f 100644 --- a/README.md +++ b/README.md @@ -4,13 +4,23 @@ ### Component base is very simple: -* Arduino NANO v3 chinese replica -* 7 segment 4 digit LED indicator with common anode, FYQ-5641BG-21 +* Arduino NANO v3 chinese replica (on Atmega-168 chip) +* 7 segment 4 digit LED indicator with common anode, FYQ-5641BD-21 (red LEDs) * 8 resistors that limiting current on LED segments, 330 Ohms, 0.25 watts -* RTC Module GEEGROW with DS1307 chip +* RTC Module GEEGROW with DS1307 chip (very basic, only RTC chip, quartz resonator, button battery, no additional memory chip) * 5x7 cm single side prototyping board * usb phone charger as power supply * 2 push buttons * 1 on/off switch * Gainta G521G enclosure (92x66.5x28ΠΌΠΌ) * 5m power cord + +### Optionally you may need: + +* Capasitor with well capacity if your charger has small capasitor on output +* Fuse, to protect your device +* DC/DC transformer if you have power supply that gives more than 5 volts or less than 4.5 volts (this will give additional surge protection if your power supply dies, this can happen after 3-5 years of uninterrupted work) + +### Additional Notes: + +My RTC module is not very accurate due to bad quartz chrystal calibration, looks like it is not exactly 32768 Hz and clock runs faster than it should be, giving about 5-8 seconds runaway per day. So i have to implement time correction in software (temperature changes during day/month/year is not very big - about 10 degrees Celsius, so we can use software compensation without thermal compensation).